Improvement in pressure gauges



J, MATTHEWS, Jr.

Pressure Gage.

No. 63,648. Patented April 9, 1867.

' I eraZZr N PErEns.PHQTO-LITMOGRAPHEH. WASHKNGTON u c JOHN MA'ITHE ws, an, or NEW YORK, N. Y.

Letters Patent No, (33,64 dated April 9, 1867.

IMPROVEMENT IN PRESSURE GAUGES.

"dip iidguulc return in in flnst "g itters gfiatnit :uih mating and of tin same.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, JOHN MATTHEWS, J12, of the city, county, and State of New York, have invented a certain new and useful Improvement on Pressure Gauges, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, forming part of this specification, and in which- Figure 1 represents a sectional view, taken transversely through the disk, of a pressure gauge constructed according to my improvement; and

Figure 2, a plan of the disk detached.

Like lcttcrsindica-te like parts in both figures.

My improvement relates to that description of pressure gauges in which a corrugated disk or plate is used that, being acted upon by the pressure of the fluidor gas to which it is exposed, has more or less motion given t) it according to the straightening or opposite action of the corrugations, as induced by variation in the pressure, and which disk is connected with a suitable indicator for noting said changes. I

To explain the nature of my improvement upon such class of gauges it is advisable to observe thatthe motion derived from the corrugated disk is necessarily very limited; and, as such motion has heretofore been in the axial line of the disk, it has been requisite to resort to a complicated system of levers. or their equivalents, to multiply the movement in order to secure along or sufficient range of action to the *tdicator; and the diffe once between the first and last motions has been so great that the slightest impertcc'intin or inaccuracy in fit of the parts'establishing the former would be very sensibly felt on the latter, therel: casing the indicator to stick or erroneously register the real pressure acting upon the disk. To obviate this the object of my invention, the nature of which consists in making the corrugations ot' the disk more sensitive on one side of the axial line of the disk than on the opposite side thereof, by, it may be, making them more numerous or wider or deeper on one side than the other, or so. as to disappear, or nearly so, on one side of the axial line of the disk, by which construction the latter has a hinged character or motion given it that produces a lateral or transverse action in relation to the axial line, and that is directly applicable to establish a leverage motion, whereby much or any mechanism for multiplying the movement is or may be avoided.

Referring to the accompanying drawing, A represents the corrugated disk, which may be made of steel or other metal, and be secured at its edges or border by being held between flanges or plates a b, the one of which may be constructed to form a cup or chamber, B, in communication by a tube, 0, with a vessel the gauge is designed to be applied to, the fluid or gas, in case the pressure be from the inside, entering by the tube 0 to act upon the disk either directly or through the intervention of a flexible protecting diaphragm, d or, in case the pressure be from the outside, the action on the disk being reversed, by the tube 0 come municating with the vacuum, or atmosphere or gas of lesser pressure on the inside than outside. The corrugations e of the disk A are represented as gradually disappearing on one side of the axial line of the latter, as at f, whereby pressure operating to straighten or exert an opposite efi cct upon the corrugations accordingly as such pressure is increased ordiminished, will give to said disk and its arm or pointer, C, a leverage action or lateral movement, as it were, from the side or part f, as a fulcrum or centre of motion whereby, upon the arm or point-er C being sufliciently extended, a length of range at its outer end is secured which may suifico to mark the changes on an indicator dial, D, without the aid of intervening mechanism, or with the aid of a less number of parts or such wide difference between the first and last movements, where the rod C is employed to operate a separate pointer, as is necessary with the ordinary disk having an equality in the corrugations all round and moving in an axial line, in which case no extension of the rod C increases its motion at the outer end. Thus, my improvement obviates the objections named to the corrugated disk gauge as heretofore constructed, while it retains all the advantages of such a form of pressure gauge.

To'make more perfect or enlarged the action of this, my improved gauge, audio prevent liability to buckle of the disk, as it is apt to do qhen crossing a plane or level, I prefer to give to said disk at more or less concave or conical form in its normal shape, as represented in the drawing, whereby it is never made to occupy or cross a straight plane or level, and, consequently, buckling is avoided- This, my improved pressure gauge, is applicable to all purposes to which pressure gauges generally are usually suited or may be applied, including steam boilers, soda-water apparatus, and other objects or purposes.

What I claim as my invention, and desire to secure by Letters Patent, is-

The corrugated disk, made more sensitive or capable of greater action on one side of its axial line than on the opposite side thereof, by giving a varied or unequal construction to the corrugations, substantially as and for the purpose or purposes specified.

JOHN MATTHEWS, Jn.

Wi tn esscst J. W. Ooonss, G. W. Rain). 

